The Modular Rail System allows you to mount various parts on your bike quickly and easily. A mounting rail is integrated inside the down tube so you can attach a water bottle or bag, for example, in any position you want.The magnetic Fidlock mounting system ensures parts are fastened securely and is easy to use. Thanks to its minimalistic design it can be mounted on smaller frame sizes as well. Only compatible with Winora, Koga and Haibike eBikes.